3&#39;-halogen-benzoyl-2-benzoic acid-4&#39;-sulphonic acids and process of making the same



Patented June 18, 1940 UNITED, STATES PATENT OFFICE 3'-HALOGEN-BENZOYL-2-BENZOIC ACID-4'- SULPHONIC' ACIDS AND PROCESS OF MAKING THE SAME Sebastian Gassner and Berthold Bienert, Leverkusen-I. G. Werk, Germany, assignors to General Aniline & Film Corporation, a corporation of Delaware No Drawing. Application January 24, 1939, Se-

rial No. 252,592. In Germany January 25,

7 Claims. (01. 260-507) The present invention relates to 3'-ha10genbenzoy1-2-benzoic acid-4'-sulphonic acids and to a process of making the same.

These compounds can be represented by the subjecting, for instance, the 3'-halogen-benzoyl- Z-benzoic acid-4'-sulphonic acid to the action of concentrated sulphuric acid at an .elevated temperature the 2-chloro-anthraquinone-S-sulform l phonic acid is obtained which, for instance, by 5 replacing the chlorine atom in 2-position is transnsm- (JO-O formed in valuable starting materials for the production of dyestufis. x 00011 The following example illustrates the invenl Where X is halogen tion without, however, restricting it thereto, the

One object of our present invention is to pro- Part5 belng y Welght! vide a method for preparing 3-halogen-benzoyl- Example Z-benzoic acid-4'-sulphonic acids. Another ob- A solution of ject of our invention resides in the new compounds which are obtainable by our new process. part? of 3 ,4 y1- -benZo1c We have found that 3'-halogen-benzoyl-2-ben- 0 g 50 zoic acid-4'-sulphonic acids are obtained by causparts a 5% Sofia h h ing salts of 3,4-dihalogen-benzoyl-2-benzoic par 5 0 CW5 a lzed Sodlum S D te 1n acids to react with sulphites in aqueous solution. parts of Water 29 P ferably w start from an alkali metal salt of is heated in an autoclave at a temperature of 29 a 3Z4-dihalogen-benzoyl-2-benzoic acid which 175 C. until in a test portion when acidified no may be obtained by neutralizing the acid emstarting material can be detected. When the reployed with an alkali liquor. As sulphite we action is finished the crude sodium salt of the preferably employ also an alkali sulphite. It 3-chlorobenzoyl-2-benzoic acid-4-sulphonic acid could not be expected that only the halogen t which corresponds to the following formula in 4'-position is replaced by the sulphonic acid group without replacing simultaneously the halo- NaOaS- (Jo- 3 gen atom in 3'-position as it was'known that re- 1 placing a halogen atom in 4'-positio-n makes a 01 00011 30 halogen atom in 3'-position more easily replacemay be obtained in a Simple manner by evapora 30 able. Therefore the course of the reaction was tion The reaction mixture may also be idifi d Su p for a man Skilled in f Also to a mineral acid reaction and the 3'-chloroben- When the Sulphite is employed zoyl-2-benzoic acid-4'-sulphonic acid separated 0958 the halogen atom 111 3"posmon 15 not as acid alkali salts, for instance by salting out placedwith sodium or potassium chloride. Colorless AS startmg mammals We preferably p crystals are obtained being easily soluble in wasalt of the 3',4'- dihalogen-benzoyl-2-benz01c acid ter and diluted alkali 1yes 'zyggg g gg aizg g g gi 3 8 Instead of sodium sulphite other sulphites, for s nuclei. Thus, for instance, the benzoyl nucleus ig gf i f Sulphate may be employed 4() may be substituted by alkyl, carboxyl or hydroxy groups. The benzoic acid nucleus may carry, for a???gfgfifi ggfg ggg fgi iggfi ig fi instance, alkyl, aryl, carboxyl and hydroxy groups. react a sulphite in aqueous solution r The reaction proceeds in known manner by caus- 2 The process which comprises causing an 4') ing the starting material i fvg temper? alkali metal salt of a 3' 4'-dihalogen-benzoyl-2- ture and, if necessary, a eeva e pressure, 0 react with an alkali sulphite. The addition of g acld fi g an alkah me a sula metal or a metal salt as, for instance copper p 3 r klre glllg cz s s 331mb cmpflses causing an alggsz Salt may be advantageous m some kali metal salt of a 3,4-dihalogen-benzoyl-2- 50 our new compounds represent valuable interbenzoic acid to react with an alkali metal sulphite mediate products for the production of dyestuffs. 1n aqueous solutlon at a temperature above 100 Thus, for instance, by the action of agents effect- 0. in an autoclave. i ing ring closure they are transformed into the 4. The process which comprises causing an alcorresponding anthraquinone compounds. By kali metal salt of the 3',4-d1ch.loro-benzoyl-2- 55 benzoic acid to react with an alkali metal sulphite in aqueous solution.

5. The process which comprises causing an alkali metal salt of the 3,4'-dichloro-benzoyl-2- benzoic acid to react with an alkali metal sulphite in aqueous solution at a temperature above 100 C. in an autoclave.

6. 3'-halogen-benzoyl-2-benzoic phonic acids.

acid-4-sul- 7. The compound of the following formula COOH SEBASTIAN GASSNER.

BERTHOLD BIENERT. 

